Help with turn signal gremlin.

ONLY for ADVANCED technical discussion about the 240sx!
Lord Umoja
Posts: 126
Joined: Sun Apr 08, 2012 1:23 pm
Car: 1993 240SX 'Vert
Location: Red Lion PA
Contact:

Post

So guys I've got a weird behavior from my left turn signal. I have checked and I have no burnt out bulbs anywhere on the car. The rear light has an 1157 and an 1157LL in the tail/brake light, an 1156LL in the turn signal, and an 1156 in the reverse light. The left turn signal essentially has 3 flash modes:

Normal, i.e. Functions just like the right side:
-When the marker lights and headlights are off and I'm coasting/accelerating.

Accelerated flash: MARGINALLY faster than the right side, but just a tiny bit. Noticeable only because I drive the car so often.
-When I press the brake pedal with the marker lights off.
-When I swap the 1156 bulb to the turn signal and the 1156LL to the reverse light.

"Bulb Out" rapid flash: just like when a bulb has burned out.
-When the marker lights or headlights are on.

I don't see any damaged wires in the tail light housing. Any thoughts? Thinking of swapping the control stalk and seeing if it's an internal issue.


User avatar
Hijacker
Posts: 15759
Joined: Wed Aug 13, 2003 4:57 am
Car: '92 240sx Convertible
'94 F-150
Location: Fredericksburg, VA

Post

A few things that are probably causing the issues:

1 - corrosion on the plugs. The flasher unit works off of a resistance value of the system. Corrosion on the plugs can throw that off.

2 - loose connectors.

3 - bad flasher unit.

I'm not sure about the last one since your problem seems to be indicative of adjacent systems affecting the turn signals. A bad flasher unit would affect the turn signals pretty uniformly. The only common area I can think of for the system is the combo lamp (this would be my first area of inspection since you mention pressing the brake pedal creates a small change in the rate). The stop lamp is a completely different circuit that doesn't go through the stalk. Check for rubs of the harness going back to the tail lights (I've personally witnessed harness issues passing by the cavity for the jack) as well as the tail lamps. As a last ditch, inspect the flasher unit and the lighting switch. If the lighting switch is at fault, I'd replace it rather than trying to wipe the contacts. If it looks like it has contacts that have going through some serious heating, it's definitely worth it to replace the switch.

User avatar
centralcoaster33
Posts: 2769
Joined: Tue Apr 05, 2005 10:41 am
Car: 240SX #5-1997
Location: Central Coast, CA

Post

Resistance is a good thing to keep an eye on. It's what makes the lights blink. When a bulb is out and the blinking doubles in speed, it's because of the resistance change. If your wires are crossed or shorted to themselves then you can cause these issues.

In addition to that and your mention of the stalk controller, well, mines been gummed up before. I took off the steering column covers, took out a screw or two and the stalk comes off in one piece. That has a large contact surface on it for the circuit and it can be covered in sticky stuff. Get some rubbing alcohol and a paper towel and clean off both sides of the contacts, then put it all back together. That fixed my signals.

Lord Umoja
Posts: 126
Joined: Sun Apr 08, 2012 1:23 pm
Car: 1993 240SX 'Vert
Location: Red Lion PA
Contact:

Post

Tried tonight to fix it by swapping to all 1157LL bulbs in the brake lights but still nothing.

I seem to have misplaced the spare control stalk I have, but I'm taking the stock one out at lunch and hitting the contacts with MAF cleaner tomorrow.

Lord Umoja
Posts: 126
Joined: Sun Apr 08, 2012 1:23 pm
Car: 1993 240SX 'Vert
Location: Red Lion PA
Contact:

Post

I think I'm going nuts. Driving in to work today, headlights off, I swear to God that the accelerated blinking is speed sensitive. On the brakes above 30mph, normal blink. On the brakes below 30mph and it speeds up.

Lord Umoja
Posts: 126
Joined: Sun Apr 08, 2012 1:23 pm
Car: 1993 240SX 'Vert
Location: Red Lion PA
Contact:

Post

Looks like it's probably not the turn signal stalk itself. Just got finished removing, cleaning, and re-installing it (in the parking lot of work, in full business dress) and yep, problem is still there.

Next check is the F***ing rats nest that is the previously installed security system. I've got this feeling that that could be the culprit, IF the security system flashes the brake lights when you lock it. That is the one spot where the brakes and turn signals all meet together.

User avatar
centralcoaster33
Posts: 2769
Joined: Tue Apr 05, 2005 10:41 am
Car: 240SX #5-1997
Location: Central Coast, CA

Post

A previously installed security system is always the starting point for electrical gremlins! Glad you thought of that... sorry about the stalk cleaning. It was a hopeful idea. Good news is that it's all clean now I guess. Hopefully you didn't get your cuffs dirty for the work shirt. I've got grease on my right cuff today from having to find loose EGR bolts and fix it about 3 weeks ago. Good times!

User avatar
Hijacker
Posts: 15759
Joined: Wed Aug 13, 2003 4:57 am
Car: '92 240sx Convertible
'94 F-150
Location: Fredericksburg, VA

Post

Lord Umoja wrote:
Tue Oct 10, 2017 10:13 am
Next check is the F***ing rats nest that is the previously installed security system. I've got this feeling that that could be the culprit, IF the security system flashes the brake lights when you lock it. That is the one spot where the brakes and turn signals all meet together.
Always start with this. Is the security system still in the car, or was it ripped out and repaired?

Lord Umoja
Posts: 126
Joined: Sun Apr 08, 2012 1:23 pm
Car: 1993 240SX 'Vert
Location: Red Lion PA
Contact:

Post

Hijacker wrote:
Thu Oct 12, 2017 7:56 am
Lord Umoja wrote:
Tue Oct 10, 2017 10:13 am
Next check is the F***ing rats nest that is the previously installed security system. I've got this feeling that that could be the culprit, IF the security system flashes the brake lights when you lock it. That is the one spot where the brakes and turn signals all meet together.
Always start with this. Is the security system still in the car, or was it ripped out and repaired?
Still in the car. It runs the central locking so I can lock/unlock with a key fob. All I did was rip out the siren. Not that I ever lock the convertible, that just invites a knife through the top.

User avatar
Hijacker
Posts: 15759
Joined: Wed Aug 13, 2003 4:57 am
Car: '92 240sx Convertible
'94 F-150
Location: Fredericksburg, VA

Post

Check the rats nest. What brand of alarm is it? Pull up a wiring diagram and see if the installer did something stupid during install. I've had a viper keyless entry system installed in my vert for well over a decade now. I only flash the parking lights, not the turn signals when I use mine.


Return to “240SX Technical Forum”